This invention relates to a pump of the type including a pump body having a control valve for controlling working fluid flow from the pump body to an actuator through a joint.
In such a pump, the joint is mechanically connected to the pump body. It is the current practice to reduce the total weight of the pump by making the pump body of an aluminum alloy. In this case, the aluminum alloy of the pump body and the iron of the joint form a galvanic junction which is susceptible to corrosion. If the pump body is mechanically connected to the pump body through a washer made of iron, the aluminum alloy of the pump body and the iron of the washer will form a galvanic junction which is susceptible to corrosion.